Control mechanism



Oct. 13, I942. L. G. MILLER 2,298,407

CONTROL MECHANISM Fileq May 14, 1941 2 Sheets-Sheet l AMPLIFIER Oct. 13, 1942. MlLLER 2,298,407

CONTROL MECHANISM Filed May 14, 1941 2 Sheets-Sheet 2 Ti g2.

' of speed adjustment of Patented Oct. 13, 1942 2,298,407 CGNTBJOL MECHAKISM Lloyd G. Miller, Beverly,

Shoe Machinery Corporation,

Mam, assignmto United Remington, N. 1.,

a corporation New Jersey Application May 14, 1941, Serial No. 393,374

1'! Claims.

This invention relates to control mechanisms and more particularly to for controlling machines for operating upon parts.

In the use of machines for performing an oper ation progressively about the of a shoe part of irregular contour, it is oi'tcn desirable to I vary the speed of operation of the work-engaging member in accordance with the shops of the part to 'be treated. The speed of the rscrh-engsging member may bear a definite relationship to the radius of curvature of theporticn oi the slice part at the operating point and may be controlled by a cam having a contour corresponding to the shape of the shoe part being operated upon. While the use of cams for controlling machines in this manner may be entirely satisfactory in many respects, it is well known that in the manufacture of shoes, changes in style often necessitate changes in the contour of the shoe and of its component parts. Thus, each new style of shoe operated upon may require a different cycle the work-engaging mem ber. Each cycle oi adjustment requires a separate cam. and the expense oil-molt cams may be excessive in factories where style changcs'ore numerous. The use of cams for the adjustment of speed of an operating member for work of this type has the further disadvantage that the machine must be stopped and partially dismantled in order to change cams. Such a change in cams calls for mechanical skill on the part of the operator and also slows up production. On the other hand, automatic mechanism for changing cams is complicated and adds greatly to the cost of the machine.

In view of the above, it is an object of this invention to provide in a shoe machine means for continuously adjusting the speed of a workengaging member according to a predetermined schedule which will overcome the disadvantages set forth above.

It is also an object of this invention to provide automatic control means for a shoe machine which may be used to produce any one of a plurality of dificrent cycles of adjustment of the speed of a work-engaging member and means for selectively controlling the work-engaging member in accordance with any one of these cycles of adjustment.

It is another object of this invention to provide in a shoe machine means for producing a cycle of adjustments in the speed of a workengaging member in accordance with the shape of a shoe part of any particular style and means for varying the time necessary to complete this same cycle of addustments so that the machine may be used to operate upon shoe parts of various sizes having the same shape.

In accordance with the above objects, a feature of the invention consists in the use of photoelectric control means to provide the desired adjustments in the speed of a work-engaging member and includes, in one aspect, a photoelectric cell, a light source therefor, a template the shape oi which corresponds to the outline of a shoe part, means driving this template in a path intercepting the beam of light from the light source to the photoelectric cell to vary the amount of light reaching the photoelectric cell from the light source in accordance with the shape of the shoev part to which it corresponds, and means operated by the photoelectric cell in response to the variations in the amount of light reaching it for controlling the speed of the work-engaging member.

Another feature of the invention consists in the provision of a plurality of templates in combination with means for selectively driving any one of these templates in a path intercepting the beam of light from the light source to the photoelectric cell, whereby the speed or magnitude of motion of the work-engaging member may be controlled for operating upon shoes or shoe parts of different shapes.

According to other features of the invention, means are provided for varying the speed at which the template is. driven past the photoelectric cell to vary the time necessary to com plete the cycle of speed adjustment which it controls, as well asmeans for interrupting the drive of the template at the completion of one cycle of operation.

The invention is herein illustrated as applied to a machine for lasting stitchdown shoes, which machine is of the same general character as that disclosed in Letters Patent of the United States No. 1,864,510, granted June 21, 1932, upon an application tiled in the name of B. T. Leveque, but it is to be understood that the invention is of general application and is not limited in its application to machines of the type shown in this patent.

The above and other important features of the invention will now be described in detail in the following specification and pointed out more ticularly in the appended claims.

In the drawings,

Fig. 1 is a side elevation, partly in section, of one form of mechanism embodying the present invention, the mechanism being shown, for purposes of illustration, as applied to a thread lastpar-' ing machine of the type shown in the abovementioned Letters Patent;

Fig. 2 is a vertical section, taken at right angles to Fig. 1, through a portion of the control mechacuring it in lasted position by means of stitches.

As disclosed in the above-mentioned Letters Patent, this machine includes in its organization a pair of intermittently rotated rolls it and i2 constructed and arranged to feed a shoe it past stitching instrumentalities including a needle l6 and looper mechanism (not shown) to wipe the upper of the shoe tightly over a last i8. These rolls have been shown in the positions which they occupy when the machine is at rest. It will be understood that the upper roll it is lowered into contact with the work when the machine is set in operation. The rolls are driven by mechanism including Horton clutches 2d and 22, links it and 26, and hell cranks ill and, 88. These bell c1 anks are mounted on a shaft 82 and are oscillated about this shaft by mechanism fully disclosed and described in the above-mentioned Letters Patent. For the purpose of drawing the upper oi the shoe ill around the last to dispose of its fullness with a smooth uniformity, as described in the aloove=mentioned patent, the upper roll it is arranged to he driven at a higher speed than the lower roll it. Accordingly, the lower roll it acts to feed the shoe as a whole past the needle to while the upper roll it), by reason of its higher speed and position, tends to gather the material of the upper slightly into each stitch made by the needle. Provision is made for adjusting th speed of rotation of the upper ieed roll it relative to the lower roll l2. For this purpose, the bell crank i8 is mounted on an eccentric portion 86 of the shaft 822 to which is connected a handle St; for rotating the shaft to alter the position of the eccentric 86. It will be understood that this effects a change in the throw of the bell crank lever 28 and thus changes the speed oi the upper ieed roll it.

This machine may also he used in the manufacture of welt shoes to last the upper and attach welting in a single operation. When the machine is used for this purpose, it is necessary to hold the shoe at an angle, as indicated in Fig. i. It is evident that when the shoe is so held, the lengths or the feed paths of the upper and lower rolls between any two points will diiier in proportion to the radii of curvature oi the reed paths between the points. When a shoe is held at such an angle, this difierenoe amounts to the combined thickness of the welt, upper and snidsole. This difference may have a considerable effect on the path lengths at the toe and heel oi the shoe where it is relatively large as compared with the radii of curvature but will have only a slight eiiect at the straight-er parts of the periphery oi the shoe where it is relatively small in respect to the radii of curvature. In order to compensate for the difference-in the lengths of feed paths, means are provided, in accordance with this invention, for continuoudy adjusting the speed of the upper roll it as the radius of curvature of the work being operated on varies.

The automatic adjusting means comprises a drive shaft 38 which is driven by a constant speed motor til and a variable speed motor 42 through a diflerential gear mechanism dd. Normally, the motors dd and 62 rotate in opposite directions and at the same speed, and the difierential gear mechanism is so constructed and arranged that no motion is imparted to the shaft 3t. Should the speed of one of the motors exceed that or the other, the shaft 39 will be set in motion, the direction and speed of rotation depending upon the relative speeds of the two motors. Thus, it will be understood that any variation in the speed of. the variable speed motor 52 will produce a corresponding motion of the shaft 3d. A worm 36 is cut on the shaft 33 and engages a gear fit to which is attached an operating arm 5t. This arm is connected to the handle by means or a rod 52 so that rotation of the drive shaft 38 will operate through the rod 52 to shift the handle 363 which changes the speed of rotation of theupper feed roll it.

For controlling the speed of the variable speed motor 32, and thus that of the upper iced roll it, a photoelectric balance system is provided. Basically, this system comprises a photoelectric cell and a light source therefor, a template, an amplifier and the variable speed motor arranged to be controlled by the photoelectric cell through the amplifier. These elements are so arranged that the normal current through the photoelectrio cell is constant at a given value. The template is arranged to be driven in a path intercepting the beam of light from the light source to the photoelectric cell and any change produced by this template in the amount of light reaching the photoelectric cell from the light source causes a variation away irom the balance value in the current flowing through the cell. This variation is amplified: and controls the variable speed motor which is arranged so to move the template relative to the photoelectric cell that the current therethrough again approaches the given balance value. The motion produced by the motor in perioing this function is utilized to perform any desired additional operation. Such a photoelectric cell balance system requires only a small slit opening in front of the photoelectric cell and is consequently quite accurate. The above-mentioned device will now be described. as applied to the machine illustrated herein, all of its elements being contained in a control box 58 which is fastened to the frame of the machine.

As shown in Fig. 2, a photoelectric cell dd is positioned behind slits and ill, formed in suitable dlaphragms upon which light from a light source 58 is focused by the lenses The diaphragm containing the slit 5?, the light source 88, and the lenses lid are mounted in a tube-ti extending through the cover of the control box so that they may be removed for inspection or replacement. The template is herein illustrated as an endless strip or loop or motion picture rilmand has a darkened surface of varying width, as shown at 63 in Figs. 1 and 3, to form an outline which corresponds in shape to a desired cycle of speed adjustment of the upper feed roll it, the outline being photographically registered on the surface of the or produced thereon in any other suitable manner.

have been provided in the present embodiment of the invention. These films are supported on pairs of sprocket rolls 86 and 58 (Fig. 2), the upper pair 66 of which is splined on a shaft HI carried in bearings 14 and 16 mounted on the control box 53. Keys 18 (Fig. 2) are formed on the sprocket rolls 66 and engage a slot which is cut lengthwise of the shaft HI. These parts are so constructed that the sprocket rolls may move lengthwise of the shaft but may not revolve relative thereto. The lower sprocket rolls are mounted on a shaft 80 journaledrin ears 82 provided at the lower end of a slide 84 which is mounted for movement in slideways 88 formed by supports 81 and cover plates 88, these parts being secured together by screws 89. A pair of ears 9!] at the upper end of the slide 84 confine the movern nt of the upper sprocket rolls 58 lengthwise of the shaft 10 and a washer 92 (Fig. l) positioned between the sprocket rolls 86 on the shaft '10 maintains'the sprocket rolls at the proper separation. It will be understood that movement of the slide 84 in the slideways 88 causes movement of the template films Hand 64 relative to the photoelectric cell 54 as a unit in a. direction parallel to the shaft 10. The template films 62 and 64 are moved past the photoelectric cell in a direction indicated by the arrows in Fig. 1 by means of a variable speed motor 94 which is arranged to drive the shaft 10 through a friction clutch 95. As indicated in Fig. l. the slide 84 has been so positioned relative to the photoelectric cell that the template film 62 is located in front of the slit 58. the other template film being ineifective at this time to control the light passing to the photoelectric cell.

As the template film 62 is driven past the slit 556 by the motor 94, it produces variations in the amount of light reaching the photoelectric cell at from the light source 56 and thus varies the amount of current flowing through the photoelectric cell. The variation in the current from the balance value is amplified by an amplifier Q8 and this variation in current is utilized to control the speed of the variable speed motor 42. The variation in speed of this motor produces motion of the shaft 38', as has been described above. For the purpose of moving the template film relative to the photoelectric cell 54 in a direction parallel to the shaft 70 in order to return the current flowing through the photoelectric cell to the balance value, a rack I00 secured to an extension 902 of the slide 85 is driven from the worm on the shaft 38 through gears lot and tilt. Thus, the variation in the speed of motor d2 operates not only to actuate the arm 5% but also to return the template film 62 to a position such that the current flowing through the photoelectric cell again approaches its balance value.

l i 'hen the machine is set up for use with any particular template, it is necessary to adjust the position of the slide 84 relative to the photoelectric cell l'n -l so that the amount of light allowed to fall on the photoelectric cell at the beginning of the cycle represented by the template will correspond to the desired balance cur- For the purpose of making this adjustment. 2, hand wheel tilt is provided at the upper end or the shaft and a clutch are is provided between the shaft and the differential gear mechanism i l. When the clutch lid is disengaged. the shaft may be revolved by hand until the desired adjustment in the position of the slide as has been obtained. The machine is further adjusted by balancing the speeds of the ill motors 40 and 42 so that the output of the diiferential gear mechanism as shown by an indicator H2, is substantially zero. This adjustment is efiected by means of a control rheostat H4 associated with the amplifier 98.

The machine having thus been adjusted for operation using a particular template the outline of which corresponds to the desired cycle of speed adjustment for a given last style, the mechanism is set in operation by engaging clutches Q5 and lit by means of a treadle (not shown) which operates through treadle rods H6 and H3, lever 526, and bell crank lever I22, simultaneously, to engage the clutches. This sets the control mechanism in operation and from this point on, the adjustment of the speed of the feed roll is entirely automatic.

It is desirable to stop the motion of the template film, and hence the adjustment of the speed of the upper feed roll, at the termination of onecomplete cycle of operation. Such a cycle will normally correspond'to the length of the loop of template film 62, and the following mechamsm is provided for maintaining the clutches 96 and H8 in engagement until the entire loop of film has been driven past the slits 56 and then disengaging them. A worm lit is provided on the shaft l0 and engages a worm gear l25 which drives a cam E28. The gear ratio is such that the cam I28 will make one revolution during the time that the complete loop of film is being driven past the slits '55 and 5?. When the treadle is depressed, the clutches 56 and i it) are engaged and the cam I28 is set in motion. When the cam in has progressed a slight distance, a shoulder I on its periphery allows a pin it? on a latch 134 which is pivoted to the bearing block iii to move to the left (Fig. 1) under the action of a'spring lSd. When this occurs, a projection M8 on the latch 53 engages a pin 40 on the bell crank lever 522 and thereafter holds the treadle down until the cam has made a complete revolution and moves the latch i3 3 back to the position shown in Fig. i. This allows a spring H2 which is secured at one end to the control box 53 and at the other to a collar its on the treadlerod lid to operate and disengage the clutches Q6 and ill at the conclusion of precisely one cycle of operation.

In order to adapt the control mechanism for use with shoes of varying sizes but of the same style, it is necessary to vary the speed at which the template is driven past the photoelectric cell so that the cycle of adjustment will be completed at the time when the entire periphery of the shoe has passed the operatin point. To this end. a

speed control 3% provided for the variable speed motor Qt. This control may be calibrated directly in last sizes and adjusted by the operator in accordance with the sizes of the shoes being operated upon. A single template film may thus he used to control the speed of the upper feed roll it) for use on shoes of all sizes of the particular last to which it corresponds.

Since it may be desired to operate upon shoes or" more than one last style, econd template film fi l is provided, as shown in e. 1. If it is desired to use this (template r; stead of the template "film screws 9 and are loosened after which the slide 8-- ey be moved relative to the until the n in 6 3 occupies the position which has been occupied the film 52. The machine balanced, in the manner already described, with the template film 64 in front of the slit 5G and is then ready for operation. upon shoes of the style which corresponds to that particular template film. Although, as illustrated, only two template films have been provided, it will be understood that more than two template films could be carried on a suitable slide arranged to take the place of the slide 84.

To facilitate substitution of other template films for thosein the machine, the films may be formed with separable ends as illustrated in Fig. ,3, each end of the template film being provided with a pair of laterally extending projections I52. Registering holes I56 are so positionedin these extensions that when the ends of the films are brought together in overlapping relation with these holes in register, the ends of the template outline 63 as well as the sprocket holes I58 will be in perfect alinement. The ends of the film 52 are secured together in overlapping relation by means of a pair of U-shaped metal clips its which are designed to clamp the projections 552 on the ends of the film together. Spurs its on one arm of each u-clip are arranged to pass through the registering holes I54 in the projections I52 and engage holes It? in the other arm of the U-clip, to fasten the ends of the film together. The arms of the U-clips I68 are long enough to extend over the sprocket holes I58 at the ends of the template film and serve to reinforce the film at the Junetion. Holes I65 are provided in the arms of the U-clips to permit the teeth of the sprocket wheels 66 and 68 to pass through the sprocket holes I58,

these holes being so positioned'as to be in alinement with the sprocket holes I68 when the clips are assembled upon the film. when it is desired to change template films, the arms 'of the clips I58 are forced apart and the clips are removed after which the films may be removed from the slide.

'The new template films are then threaded overthe sprocket wheels 66 and 68, the registering holes I54 in their ends are brought together in overlapping relation, and new pairs of U-clips are applied to secure the ends of the films together.

' Assembled templates comprising loops of film and pairs of clips are shown assembled on slide 84 g in Fig. 1.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a machine for operating upon the periphery of a shoe part, a first work-engaging member, means for driving said first work-engaging member at a constant speed, asecond work-engaging member. means for variably driving said second work-engaging member in accordance with a predetermined schedule. a photoelectric cell, a light source therefor, means for causing variations in the amount of light reaching said photoelectric cell from said light source according to said predetermined schedule. and means operated by the photoelectric cell in response to said variations for controlling said last-mentioned driving means.

2. In a machine for operating upon the periph- ,member at a constant speed, a second work-engaging member, means for driving said second work-engaging member at speeds which vary according to a predetermined schedule, a photoelectric cell, a light source therefor, a template the shape of which corresponds to said predetermined schedule, means for driving said template in a path intercepting the beam of light from said light source to said photoelectric cell to cause variations in the amount of light reaching said photoelectric cell according to the predetermined schedule, and means operated by the photoelectric cell in response to said variations for controlling said second-mentioned driving means.

4. In a'machine for operating upon the periphery of a shoe part, a first work-engaging member, means for driving said first work-engaging member at a constant speed, a second work-engaging member, means for driving said second work-engaging member at varying speeds, a photoelectric cell, a light source therefor, a template comprising a loop of film with an outline corresponding to a desired schedule of tographically registered thereon, means 'for driving said template in a path intercepting the beam of light from said light source to said photoelectric cell to cause variations in the amount of light reaching said photoelectric cell from said light source according to said schedule, and

means operated by the photoelectric cell in re-' sponse to said variations for controlling said second-mentioned driving means.

-5. In a machine for operating upon the periphery of a shoe part, a work-engaging member,

means for variably driving said work-engaging member, a photoelectric cell, a light source therefor, means for causing variations in the amount of light reaching said photoelectric cell from said light source according to a predetermined cycle of operations, means for varying .the time required for one complete cycle of operation, and

ery of a shoe part, a first work-engaging member, means for driving said first work-engaging member at a constant speed, asecond work-engaging member, means for variably driving said second work-engaging member in accordance with a predetermined schedule, a photoelectric cell, a light source therefor, a template, means for driving said template in a path intercepting the beam of light from said light source to said photoelectric cell to cause variations in the amount of light reaching said photoelectric cell from said light source according to said predetermined schedule, and means operated by the photoelectric cell in response to said variations 76 means operated by the photoelectric cell in response to said variations for controlling said driving means.

6. In a machine for operating upon'the periphery of a shoe part, a work-engaging member, means for driving said work-engaging member at varying speeds, a photoelectric cell, a light source therefor, a template comprising an endless band of film with an outline corresponding to a predetermined cycle of operation of said workengaging member photographically registered thereon, a variable speed motor for'driving said template in a path intercepting the beam of light from said light source to said photoelectric cell to cause variations in the amount of light reaching said photoelectric cell from said light source according to said cycle, means for adjusting the speed of said motor to vary the time required to complete said cycle, and means operated by the photoelectric cellin response. to said variations for adjusting the speed of said first-mentioned driving means.

'7. In a machine for operating upon the periphery of a shoe part, a work-engaging member, means for variably driving said work-engaging member, a photoelectric cell, a light source therefor, a plurality of template films each of which bears an outline corresponding to a predetermined cycle of operations, means for selectively driving operations phoany one of said films in a path intercepting the beam of light from said light source to said photoelectric cell to cause variations in the amount of light reaching said photoelectric cell according to the corresponding outline on the dim, and means operated by the photoelectric cell in response to said variations for controlling said firstmentioned driving means.

8. In a machine for operating upon the periphery of a shoe part, a work-engaging member, means for variably driving said work-engaging member, a photoelectric cell, a light source therefor, a template, means for driving said template in a path intercepting the beam of light from said light source to said photoelectric cell to cause variations in the amount of light reaching said photoelectric cell from said light source according to a predetermined schedule, and means operated by said photoelectric cell in response to said variations for relatively shifting said template and said photoelectric cell to maintain the amount of light reaching said photoelectric cell at a substantially constant value.

9. In a machine for operating upon the periphery of a shoe part, a work-engaging member, means for driving said work-engaging member at varying speeds, a photoelectric cell, a light source therefor, means for causing variations in the amount of light reaching said photoelectric cell from said light source according to a predetermined schedule, a constant speed motor, a variable speed motor controlled by said photoelectric cell in response to said variations, a drive shaft, means connecting said motors to said drive shaft so that the speed and direction of rotation oi! said snaft depend upon the difference in the speeds of said motors, and means operated by said drive shaft for varying the speed of said driving means.

10. In a machine -ior operating upon the periphery of a shoe part, a work-engaging member, means for driving said work-engaging member at varying speeds, a photoelectric cell, a light source therefor, means for causing variations in the amount of light reaching said photoelectric cell from said light source according to a predetermined schedule, a constant speed motor, a variable speed motor controlled by said photoelectric cell in response to said variations, a drive shaft, means connecting said motors to said drive shaft so that the speed and direction of rotation of said shaft depend upon the difference in the speeds of said motors, means driven by said shaft for adjusting the of the driving means for said work-engaging memher, and means also driven by said shaft ror adjusting the amount of light reaching said photoelectric cell so that it is maintained at a substantially constant value.

11. In a machine for operating upon the periphery of a shoe part, a work-engaging memner, means for variably driving said work-engaging member, a photoelectric cell, a light source therefor, a template, means for driving said template in a path intercepting the beam of light from said light source to said photoelectric cell to cause variations in the amount of t l ing said photoelectric cell from said according to a predetermined schedule, means operated by the photoelectric cell in re said variations for controlling said driving means, and means for interrupting the drive or" said template after a predetermined time.

12. In a machine for operating upon the periphery of a shoe part, a work-engaging men:-

ber, means for variably driving said work-engaging member, a photoelectric cell, a light source therefor, a template, means for driving said template in a path intercepting the beam of light from said light source to said photoelectric cell to cause variations in the amount of light reachmg said photoelectric cell from said light source according to a predetermined cycle of operation, means operated by the photoelectric cell in response to said variations for controlling said driv= ing means, and a one-revolution clutch associated with said template driving means for stopping the movement oi said template past said photoelectric cell at the completion of one cycle.

13. In a machine for operating upon the periphery of a shoe part, a work-engaging member, means for driving said work-engaging memher at varying speeds, a photoelectric cell, a light source therefor, a template,.means for driving said template in a path intercepting the beam of light from said light source to said photoelectric cell to cause variations in the amount of light reaching said photoelectric cell from said light source according to a predetermined schedule, means operated by the photoelectric cell in response to said variations for adjusting the speed of said driving means, a one-revolution clutch associated with said template for interrupting the movement of said template past said photo-- electric cell at the completion of one cycle, and means operated by said photoelectric cell in response to said variations for shifting said template in a direction tending to maintain the amount of light reaching said photoelectric cell at a substantially constant va ue throughout the cycle.

M. In a machine for operating upon the periphery of a shoe part, a work-engaging member, means for driving said work-engaging member at varying speeds, a photoelectric cell, a light source therefor, a template, means for driving said template in a path intercepting the beam of light irom said light source to said photoelectric cell to cause variations in the amount of light reaching said photoelectric cell according to a predetermined schedule, a constant speed motor, a variable speed motor controlled by said photoelectric cell in response to said variations, a drive snait, means connecting said drive snarr, to said motors so that the speed and direction of the I'OOEtIOIIL Of said shaft depend upon dinerences in the speeds oi said motors, means operated by said drive snarl; or varying the speed or said iii-so mentioned driving means, and means driven by said shalt tor relatively shitting said template and said photoelectric cell to maintain the amount of light reaching said photoelectric cell at a sunstantially constant value.

15. A machine for lasting stitchdoivn shoes, having in combination, a pair of iced rolls, means ior rotating one of said iced rolls at variable speeds, means for rotating the other of said feed rolls at a constant speed, and means lor adjustmg the speed of rotation of first feed roll, said means comprising a photoelectric cell, light source therefor, a template having an outline which corresponds to the bottom outline e carticular last, means for driving said temp path intercepting the beam of light said light source to said photoelectric cell to cause variations in the amount of ligi t reaching the photoelectric cell in accordance with the shape of the particular last, and means operated by the photoelectric cell in response to said varial Non-.0.

tions for controlling the speed of rotation of said first feed roll.

16. A machine for lasting stitchdown shoes, having in combination, a feed roll, means for rotating said feed roll at variable speeds and means for adjusting the speed of rotation of the feed roll, said means comprising a photoelectric cell, a light source therefor, a plurality of template films each having an outline corresponding to the bottom outline of a particular last photographicaily registered thereon, means for selectively driving any one of said template films in a path intercepting the beam of light irom said light source to said photoelectric cell to cause varia= tions in the amount of light reaching the photoelectric cell in accordance with the shape of the particular last chosen as determined by the outline on the corresponding template film, and means operated by the photoelectric cell in re sponse to said variations Zcr controlling the speed of rotation of said feed roll.

17. A machine for lasting stltchdcwn shoes,

having in combination, a feed roll. means for rotating said feed roll at variable speeds, means for adjusting the speed of rotation of the feed roll, said means comprising a photoelectric cell, a light source therefor, a template having an outline which corresponds to the bottom outline of a particular last, means for driving said template in a path intercepting the beam of light from said light source to said photoelectric cell to cause variations in the amount of light reaching the photoelectric cell in a cycle determined by the shape of the particular last, means operated by the photoelectric cell in response to said variations for controlling the speed of rotation of said teed roll in said cycle, and means for adjusting the machine for work on lasts cf the same style but of different sizm, said means comprising a variable speed motor driving said template means for adjusting the speed of said motor to vary the time required to complete said cycle.

LLOYD G. MILLER. 

